Presentation of antigenic sites from foot-and-mouth disease virus on the surface of baculovirus and in the membrane of infected cells.

We describe the construction of recombinant baculoviruses displaying on their surface and in the membrane of infected cells the small, immunodominant antigenic site (site A) or the large polyprotein (P1) coding for the four structural proteins of foot-and-mouth disease virus (FMDV). The coding sequences were inserted in the amino-terminus of gp64, the major glycoprotein of the baculovirus Autographa californica nuclear polyhedrosis virus (AcNPV). Following infection of insect cells with the recombinant baculoviruses, the cellular localization of the chimaeric proteins as well as their presence in the surface of extracellular viruses was assessed by immunofluorescence microscopy and Western blot. The antigenicity of the recombinant viruses was studied by competitive ELISAs, which showed that although both recombinant viruses were able to compete with FMDV-specific monoclonal antibodies (MAbs), their patterns of reactivity were different. The results suggest that this eukaryotic display system could be an alternative method of presentation of foreign antigens in a multimeric form as a new approach to biosynthetic vaccines.